Imidazopyridine Electron Transport Layer for OLED Voltage and Efficiency

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Solution Overview

Problem

Conventional organic light emitting diodes (OLEDs) suffer from unsatisfactory driving voltages, luminance, current densities, power efficiencies, and lifetimes due to limitations in electron transport layer materials.

Innovation Solution

The use of imidazopyridine-based compounds, specifically represented by Formula 1, which exhibit high electron transport capabilities, are integrated into the OLED structure as an electron transport layer, enhancing the device's performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional electron transport layer materials (oxadiazoles, thiadiazoles, pyrimidines) are used, then the OLED structure is simple and manufacturing is easy, but the driving voltage is high, luminance is low, current density is low, power efficiency is poor, and lifetime is short

Engineering Contradiction:
Improveease of manufactureVSAvoiddriving voltage
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the electron transport layer by introducing imidazopyridine-based compounds with specific molecular structures (Formula 1) containing nitrogen-containing heterocyclic rings. This chemical parameter change results in improved electronic properties including lower driving voltage, higher electron mobility, and better overall device performance while maintaining ease of manufacture through conventional OLED fabrication processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material design by combining the imidazopyridine core structure with various substituent groups (aryl, heteroaryl, alkyl, alkoxy groups) to create optimized electron transport materials. These composite molecular structures achieve superior electron transport capabilities and device performance characteristics compared to conventional single-structure materials

Inventive Principle:
Principle #40Composite materials

2Device complexity

If conventional electron transport layer materials are used, then the device structure is simple, but the luminance and current density are insufficient

Engineering Contradiction:
Improvedevice complexityVSAvoidluminance
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent achieves enhanced luminance and current density by changing the electronic parameters of the electron transport layer through imidazopyridine-based compounds. The specific molecular structure with nitrogen-containing heterocyclic rings improves electron injection and transport efficiency, leading to higher current density and luminance output without complicating the overall device structure

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional electron transport layer materials are used, then the manufacturing process is simple, but the power efficiency and lifetime are unsatisfactory

Engineering Contradiction:
Improveease of manufactureVSAvoidpower efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent improves power efficiency by changing the electronic transport parameters through imidazopyridine-based compounds. The optimized molecular structure reduces energy loss during electron transport, improves electron-hole recombination efficiency in the emissive layer, and enhances overall device power efficiency while maintaining simple manufacturing processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent addresses lifetime issues by using stable imidazopyridine-based compounds that resist degradation under operational conditions. These materials provide enhanced chemical and thermal stability, extending device lifetime without requiring complex manufacturing or additional protective layers

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The imidazopyridine-based compounds improve OLED efficiency, reduce driving voltage, increase luminance, and extend the device's lifespan, resulting in higher current densities and better power efficiency.

Implementation Method 1

The electrons injected from the cathode migrate to the emissive layer via the electron transport layer

Methodology Applied
Scientific EffectElectron transport: Conduction (electrical)

Implementation Method 2

When the excitons drop from an excited state to a ground state, fluorescent molecules of the emissive layer emit light

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP1925618B1Imidazopyridine-based compounds and organic light emitting diode including organic layer comprising the imidazopyridine-based compounds
Publication Date: 2013.03.13 SAMSUNG DISPLAY CO LTD
  • EP1925618B1 patent drawingFigure 1
  • EP1925618B1 patent drawingFigure 2
  • EP1925618B1 patent drawingFigure 3

AI summary

Imidazopyridine-based compounds of Formula I and organic light emitting diodes (OLEDs) comprising organic layers including the imidazopyridine-based compounds are provided. The organic light emitting diodes including organic layers having the imidazopyridine-based compounds have low driving voltages, high efficiencies, high luminance, long life-times and low power consumption.